The invention pertains to a method and to an apparatus for controlling the brake system of electric drive vehicles according to the introductory clauses of the independent claims.
A brake system for motor vehicles with electric drive is known from WO-A 93/01,959, in which a conventional friction brake and a regenerative brake acting via the drive motor or motors of the vehicle are used for braking. When the brake pedal is actuated, the ratio between the braking force of the regenerative electric brake and that of the conventional friction brake is determined in such as way as to optimize the energy recovery via the regenerative brake. In addition, the action of the regenerative brake is modified as a function of the release rate of the accelerator in such a way as to simulate the action of the drag torque known from conventional vehicles which occurs when the accelerator is released.
Because, in the prior art solution, modifications are made to the actions of both the friction brake and the electric regenerative brake during a braking process, complicated measures are required to ensure that the modifications of the actions of these two types of brakes during the braking process are coordinated with each other and so that the influences which they exert on each other are taken into account.
The task of the invention is to simplify the control of a brake system of electric drive vehicles with both friction and electroregenerative brakes without the occurrence of any significant impairment to the energy recovery during the deceleration of the vehicle.
This goal is achieved by means of the invention herein.